It is common that a vehicle, such as an automobile, is equipped with an airbag device which inflates and deploys an airbag inside the vehicle to absorb an impact exerted on an occupant in an emergency such as collision or rapid deceleration. Typically, this airbag device has an airbag that is folded under a normal condition and is inflated and deployed in an emergency; an inflator that supplies gas to the airbag; a retainer that fixes the airbag and the inflator; and an airbag cover that covers the airbag.
In the event of a collision or rapid deceleration of the vehicle, gas is supplied from the inflator to the airbag and the airbag is inflated, the airbag cover is cleaved, and the airbag is released to the inside of the vehicle to be inflated and deployed. In particular, in a front passenger seat airbag device, the airbag is inflated and deployed in a space defined by an instrument panel, a windshield (front glass) and the occupant.
There are many retainers made of a metallic material to stand against an impact when the airbag is inflated and deployed or the occupant collides with the airbag (for example, refer to Japanese Patent Application Publication No. 2001-097162 A). In the airbag device disclosed in Japanese Patent Application Publication No. 2001-097162 A, a retainer made of a metallic plate is fixed to a portion of the instrument panel by use of an installation bolt.
In addition, a retainer, of which a portion is made of a synthetic resin for the weight reduction thereof, has already been proposed (for example, refer to Japanese Patent Application Publication No. 2000-326813 A). In the airbag device disclosed in Japanese Patent Application Publication No. 2000-326813 A, a lower retainer for retaining the inflator is made of a metal, and an upper retainer for retaining the airbag is made of a synthetic resin. The lower retainer is fixed to the upper retainer by use of a bolt, and a protrusion of the upper retainer is fitted into the airbag cover (lid) to be fixed. In this configuration, a weight reduction is accomplished by the upper retainer and an impact is absorbed by the lower retainer.
As illustrated, in many cases, the retainer is fixed to the instrument panel or the airbag cover by use of a fastener such as a rivet or a bolt, or the protrusion of the retainer is fitted into the instrument panel or the airbag cover to be fixed, and thus the retainer is positioned. However, in recent years, as disclosed in Japanese Patent No. 3822578 B2, a configuration is increasing in which a hook arranged in the retainer is engaged with an opening formed in the airbag cover (lid) while being movable relative to each other so that the retainer can be positioned in a floating shape. In this configuration, an impact from the airbag is mitigated and assemblability is improved.